Plural actuated press means for a press-charging system



April 23, 1968 BRUDE'R ETAL 3,379,124

PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM Filed April 26,1966 6 Sheets-Sheet 1 INVENTORS gwl ATTORNEY April 23, 1968 KQBRUDER ETAL 3,379,124

PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING sysmv,

Filed April 26, 1966 6 Sheets-Sheet INVENTORS A0424 52095? W41. 70 I2HflJGJ BYGQUL je n ATTORNEY April 23, 1968 BRUDER ET AL 3,379,124

PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM Filed April 26,1966 I 6 Sheets-Sheet 5 I I .2 Y 1 .I :l Q n; I; O 101 FIG. 6A

m y L i 5 INVENTOR s KARL B B (/05 9 BY w, 762 H 0': 6.: 90 16- ATTORNEYApril 23, 1968 K. BRUDER ET AL PLURAL ACTUATED PRESS MEANS FOR APRESS-CHARGING SYSTEM 6 Sheets-Sheet 4 Apr INVENTORS E4 0 4 8 e a 06G wr. 76a 1419'; 4 5 BY ATTORNEY A ril 23, 1968 K. BRUDER ET AL PLURALACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM -.'-e:i April 26, 1965fi -N 6 Sheets-Shet Ill INVENTORS 42 a a E pee swan-e 14: 66:

ATTORNEY SYSTEM April 23, 1968 K. BRUDER ET AL FOR A PRESS-CHARGINPLURAL ACTUA'IED PRESS MEANS 6 Sheets-Sheet 6 Filed April 26, 1966 m g aT NE m E 4 0 V r m m 5 BYQQarl United States Patent 3,379,124 PLURALACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM Karl Bruder, Krefcld,and Walter Hiisges, Dulken, Germany, assignors to Firrna G. Siempelkamp& Co., Krefeld, Germany, a corporation of Germany Continuation-impart ofapplication Ser. No. 534,324,

Mar. 15, 1966. This application Apr. 26, 1966, Ser.

Claims. (Cl. 100-437) This application is a continuation-in-part of ourcopending application Ser. No. 534,324, filed Mar. 15, 1966 and entitledPress-Charging Apparatus.

The charging of presses and especially multiplaten presses for theproduction of coherent plate or sheet-like boards of a variety ofcompositions has become common in the art. Such presses have been usedfor the compaction of loosely coherent sheet material and for thecompression of laminatable bodies. In general, the mats of looselycoherent material to be formed into fiberboard, pressed board, hardboard or the like, and the multi-layer stacks to be laminated into aunitary structure (e.g. plywood, veneer composites, door structures) arefed to the platens of the press upon so-called charging tablets whichare withdrawn from the press and the stacks or bodies stripped from thetablets during the withdrawal operation. Systems using throughgoingcharging plates and trays remaining in the press are highly effectivefor the purposes indicated although they do have the disadvantage that,subsequent to the discharge of the finished board or sheet rom theplaten press, an afterhandling of the charging plates and their returnto the charging station is required. On the other hand, the use of suchcharging plates or trays greatly facilitates the handling of looselycoherent sheet materials prior to their introduction into the press andeliminates the need for complex equipment for withdrawing chargingtablets or the like while leaving the sheets to be compressed within thepress.

In press installations in which the plate-like material to be compressedinto coherency are laminated from a plurality of layers of wood or woodcomposition, it has generally been the practice to provide a collectingstation along the path of the plates at which the successive layers arestacked subsequent to the application of adhesives or glue to theprevious layer or to the subsequent layer to be applied. The stacks thuscomprise a plurality of layers, generally thin and wavy, with glue orother adhesive material sandwiched between them and adapted to becompressed at elevated temperatures to form coherent plywood, veneer ordoor structures. The charging station can then comprise a rack orsupport adjacent the press and provided with a corresponding number ofpresscharging stages each algined with a respective press platen andadapted to receive the material directly in the event the stages areprovided with charging tablets, or to receive press-charging plates ortrays. In either case, a mechanism including a plurality of arms hasgenerally been required to advance the sheets upon their respectivecarriers into the press. This advancing operation simultaneously forcesthe completed board or plate out of the press for stacking at thedischarge side thereof.

In our copending application mentioned above, we describe an apparatusfor the charging of multiplaten presses with the aid of charging tabletswhich carry the laminateble stacks into the press and are subsequentlywithdrawn therefrom with the stacks being stripped from the tablets toremain in the press. According to the improved system of thatapplication, the press-charging station is provided with a plurality ofvertically spaced charging tablets corresponding in number to the numberof levels of the 70 press and shiftable relatively thereto between thecharging station and an inserted position of the charging tablets inwhich they are received between the platens of the press. Theplate-carrying arms co-operate with a plurality of sliders having alost-motion connection therewith to align the edges of the laminatablebodies so that the respective layers are not askew during thecompression stroke. The slider means is displaceable relatively to theplate-shifting and is provided with abutment means engageable with therear edge of each of the laminatable bodies or stacks on the chargingtablets for aligning the rear edge of each stack during a limitedforward motion of the slider means prior to its entrainment of theplatecarrying means. Thereafter, the slider means entrains theplate-carrying means to advance the charging tablets into themultiplaten press while concurrently shifting the previously pressedbodies therefrom, the slider means being then withdrawn to its limitedplay to disengage the abutment surfaces from the rear edges of thebodies and permit stripper elements to be inserted between theseabutment surfaces and the bodies. Upon entrainment of the plate-carryingmeans with the slider means in the withdrawal direction, the stripperelements retain the bodies in the press and the tablets are redisposedat the charging station for subsequent receipt of stacks of laminatablelayers.

We have also observed that during the feeding operation in which thestacks of laminatable layers are deposited upon the Charging tablets,the wrinkled or wavy characteristics of the layers frequently results ina disalignment thereof or the catching of one or more layers upon edgesof the charging stages or tablets. Accordingly, in our copendingapplication Ser. No. 534,231 filed Mar. 14, 1966 and entitled Apparatusfor the Charging of Multiplaten Presses, we point out that a verticallyshiftable feed plate can be disposed adjacent the presscharging stationfor receiving the laminatable stack to be transferred to the respectivecharging tablets, this plate being elevatable from a loading position inwhich the feed plate receives the body to be compressed and a dischargeposition at which the body can be advanced onto the respectivecharging-station stage. The improvement of this latter applicationresides in the combination with this feed plate of an abutment meansdisposed in the region of the discharge position of the feed plate andengageable therewith for defining a limiting position of the feed plateabove the receiving surface of the respective stage of the chargingstation. Means is then provided for shifting the laminatable stack onthe feed plate onto the receiving surface disposed therebelow in thedischarge position of the feed means. Abutment rails are provided abovethe feed plate and form a stop therefor while a slide means isdisplaceable along these rails and engages a rearward edge of thelaminatable stack for advancing the latter between the rails and thefeed plate onto the respective tablets of the press-charging means.

In general, it has been found with laminatable stacks of relatively thinmaterial and, most commonly, with such materials as are to be joined byadhesives and the like, that regardless of the speed of thepress-charging operation, a preliminary drying of the glue may set inand the press-charging operation may involve a relative shifting of thelayers and, consequently, disalignment thereof; the formation ofprotuberances or wavy portions results from the absorption of glue bythe material, a tacking of the layers by the drying of the glue in anundesirable position, or may be present even before the glue is applied.

provide an improved press-charging system for obviating thedisadvantages above and extend the principles originally set forth inour copending applications Ser. No. 534,324 and Ser. No. 534,231.

A further object of this invention is to provide a presscharging systemfor multiplaten presses and, especially for the processing oflaminatable stacks of relatively thin sheet materials in which wavyformations of the sheets of laminatable material are avoided, anypre-existing irregularities and wavy formations rendered ineifective indetrimentally affecting the process, disalignment of the layers duringthe press-charging stroke can be obviated, and the dangers of prematuredrying of the glue in improper positions of the layers are precluded.

Yet a further object of this invention is to provide a press-chargingsystem in which the laminatable stacks of thin layers can be handledpositively through the feeding of these layers to the charging stagesand, subsequently, during their advance into the press.

These objects and others which will become apparent hereinafter areattained, in accordance with the present invention, in a press-chargingsystem in which a press charging station is disposed adjacent amultilevel press and is raisable and lowerable for successive alignmentof the stages of the press-charging station at a feeding level wherebythe stacks of laminatable sheets can be advanced onto the respectivestages of the charging station and, when the latter is fully elevated,all of the stages of the charging station can be emptied simultaneouslyinto the press. The invention resides to large measure in the provisionof a hold-down unit at each of the stages of the press-charging station,such unit permitting introduction of the stacks of material during thestepwise elevation of the charging station but thereafter clamping thestack against the charging surface (i.e. conveyor, withdrawable tablet,or throughgoing plate) until the charging station is to besimultaneously emptied into the press. It has been found that thisprecompression of the stacks in the charging station permits a smoothingof predistorted layers (i.e. layers which have developed undulationseven prior to the application of glue thereto), ensures a relativeimmobility of layers during the charging operation, and clamps thelayers in place so that any preliminary setting of the glue occurs withthe layers in their desired positions.

Advantageously, the hold-down means includes a holddown element in theform of a plate overlying the receiving surface of each stage of thecharging station and raisable and lowerable by means of a lever-linkagearrangement connecting each plate with a common actuating member of thefirst actuating means carried slidably upon the charging station rackand provided with fluidresponsive actuating means for shifting theactuating member with respect to the rack to swing the levers and raiseand lower the holddown plates.

According to a further feature of this invention, each of the leverlinkage is mounted upon or coupled with the actuating member via alost-motion coupling operable by a second actuating means upon thepositioning of each stage at the infeed :level of the feeding means forindividually raising the hold-down plates to permit introduction of thestacks of laminatable sheet material upon elevation of the rack;fluid-responsive means disengages the lost-motion coupling means andpermits the plates to close upon the stack previously inserted. Thus,the present invention provides actuating means common to all of theplates and designed to raise the plates and release all of the stacks ofmaterial after an initial precompression for advance into the press. Inaddition, each plate may be individually raised to permit introductionof the respective stack. Compressed charging plates and lever linkagemay be so arranged that the plates not only are capable of verticalmovement but are adapted to swing out substantially horizontally and/ orcome to rest against the underside of an upper stage during discharge ofthe 4 press-charging station. Furthermore, the linkage means can includea shaft carried by the successively higher stage and connected with thecharging plate with the aid of a lever keyed to this shaft. Theactuating member can be a vertical bar while the coupling means can beslide bodies carried thereby.

The above and other objects, features and advantages of the presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. 1 is a side-elevational view of a system for the charging of amultiplaten press in accordance with this invention;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a side-elevational view of one charging stage of theapparatus, somewhat enlarged with respect to FIG. 1 and illustratedfragmentarily;

FIG. 4 is a plan view of a portion of the charging stage, illustrated inFIG. 3, partly broken away;

FIG. 5 is a side-elcvational view of the hold-down actuating means forthe apparatus, partly in section and drawn to an enlarged scale;

FIG. 6 is a fragmentary elevation view of the means for individuallyoperating the hold-down plates; and

FIG. 6A is a view taken in the direction of arrow VI-A of FIG. 6.

In FIGS. 1 and 2, we show somewhat schematically a system for thecharging of multiplaten presses with laminatable multilayer stacksadapted to be compressed in the presence of heat and/ or bonded with theaid of adhesives into coherent and unitary sheets or boards. Suchpresses are wellknown in the art and can, for example, be of any of thetypes described and claimed in the commonly assigned US. Patents, Nos.3,050,777, 3,209,405, and

3,241,189; in accordance with this invention, these presses are employedfor the bonding of relatively thin wood layers to one another inrespective stacks to form furniture veneer, door structures, plywod andthe like.

General description In accordance with the principles of this invention,the multiplaten press 1 is flanked by a charging station 2 adapted tofeed the individual stacks, which may be provided upon charging plates,shiftable platforms or tablets or movable conveyor hands, into the pressto displace the previously compressed boards therefrom and introduce thestacks to be compressed. As set forth in our copending application Ser.No. 534,324, filed Mar. 15, 1966, and entitled, Press-ChargingApparatus, the charging station 2 comprises a vertically shiftable frame3 carrying a plurality of vertically spaced or stacked charging stagesor levels corresponding in number to the press stages or levels of themultiplaten press 1. ,The levels 4 of the press-charging station 2 are,of course, respectively alignable with the platens lat of the press 1for the simultaneous advance ofall the stacks of the charging station.

Discharge station The charging station 2 is disposed in front of or atthe inlet side of the press (FIG. 2) while behind the press at itsoutlet side a discharge station 60 is provided, this discharge stationcomprising a collecting conveyor 5 and a stacking device 6 for thecompressed and bonded board. As will be apparent from FIGSbl and 2, thecolr lecting conveyor 5 comprises, a plurality of transversely spacedendless conveyor belts 5a carried by respective arrays of guide rollers5b upon arms5c swingable jointly about a respective pivotal axis 5d towhich the arms are keyed. The trough-shaped shaft 50? is, in turn,mounted in a support frame 5e and rotatably receives a drive shaft 5which is carried in bearings (not shown) of the upwardly opensemicylindrical pivot shaft 5d. The arms 50 are interconnected by bars5g to which the platens 5/1 of the fluid-operated cylinders 5i arepivotally afiixed, these cylinders 5i being swivelably mounted at 5i tothe frame 5e (FIG. 1). A drive pulley 5k is likewise carried by theframe 5e and is connected via a belt 5l to a driven pulley 5m on theshaft 5 to provide continuous rotations of the belts 5a. Thus, theunitary laminated board 5p deposited upon the belts 5a of the pull-outor discharge device 5 will be carried up over the shaft 5 and depositedupon the stacker 6. The pull-out unit 5 is sWinga-ble via thefluidresponsive means 511, Si, 5 as indicated in broken lines in FIG. 1.

The stacking device 6 comprises a roller platform 6a Whpse rolls 6b aretransversely spaced but mutually parallel and extend transversely to thedirection of movement (arrow 60) of the unitary goods out of the press;the rollers are provided with a common drive belt 6d which is operatedby a motor 6e via a speed-reduction transmission 6 designed to rotatethe roller 6b and thereby shift the entire stack out of the stackingdevice 6 in the direction of arrow 60. The rollers 6b are mounted in aframe 6g flanked by uprights 6h and 62 at opposite ends of the frame 6g.The uprights 6i are connected by a crossbar 6 and are displaceable inthe direction of arrow 6k to align the corresponding edges of the stackboard disposed thereon; hydraulic means (not shown) can be provided todisplace the uprights 6i and the crossbar 6 in the direction of arrow6k, the opposite edges of the board being retained by the uprights 6h.

Stripper means As described in our copending application Ser. No 534,324entitled Press-Charging Apparatus, the press is charged by displacingthe stacked laminated sheets onto the respective platens in the pressupon respective pallets which are then withdrawn while stripper meansretains the stacks of the various levels from being retracted with thepallets. The stripper means, generally designated 7, is disposed betweenthe press-charging station 2 and the press 1 (FIG. 2).

The stripper means 7 can comprise a pair of inwardly extending arms 7aand 7b adapted to project into the path of the stack upon each level andshiftable in respective holders 7c, 7:! in the direction of arrow 7e and7 respectively. For this purpose, the arms 7:: and 7b may be constitutedas racks engagea'ble by pinions within the mechanisms 7c and 7d or asthreaded bodies but with a nut rotatable in each mechanism 70 and 7d inopposite senses to advance and retract the stripper arms 7a and 7b. Itwill thus be apparent that, after the stack-carrying pallets arerespectively introduced into the press and overlie the respectiveplatens 1', 1" thereof, the stripper arms 7a and 7b are advancedinwardly and retain the rear longitudinal edge of each stack (a pair ofsuch anms being provided for each press level) to prevent retraction ofthe stack with the respective pallet during the rearward movementthereof. The stacks remain in the press during the stroke thereof, thearms 7a and 7b being retracted subsequently to the withdrawal of thepallets but prior to the next advance thereof to permit a further set ofstacks to be introduced into the press and to dislodge finished boardtherefrom.

Charging station The press-charging station, in accordance with thepresent invention, comprises the frame 3 which as can be seen in FIG. 1,is vertically shiftable upon guide rails 3a in a well 8a of thefoundation 8 of the installation. The Well 8a is dimensioned to receivethe entire vertical array of pallets and their rack 3 so that thesuccessive pallets can be loaded with the respective stacks of laminatedsheets at an infeed level represented at 9 with, for example, the aid ofa charging device as is described and claimed in our copendingapplication Ser. No. 534,231, filed Mar. 14, 1966, and entitledApparatus for the Charging of Multiplaten Presses. As described in thatapplication, the rack of pallets is raised in a stepwise manner and thesuccessive stacks of laminated sheets are disposed upon successivelylower pallets, the pallets being shifted jointly into the press andwithdrawn concurrently only after each of the pallets has been charged.Vertical displacement of the rack 3 is effected with the aid of acounterweight 3b connected via cables 30 with the rack 3, the cables 30passing over idler pulleys 3d. A further pulley 3e driven by a motor(not shown) rotates the pulleys 3d to raise and lower the rack 3. Thepallets 3g are provided with longitudinally extending ribs 311 designedto receive the stacks of laminated sheets and to co-operate with sweeperplates 3i carried by arm 3 for straightening of the rearward edge of theplates. The straightening means is fully described in our applicationSer. No. 534,324 entitled, Press-Charging Apparatus, and it will beunderstood that the present discussion thereof is to be taken wherenecessary with the disclosure of this latter application.

Stack-straightening means The stack-straightening means for theindividual laminated stacks of the respective pallets is generally shownat 7 0 and comprises a carriage a rollingly supported on a rail 70b andhaving an arm 70c depending from the carriage. The arm can be providedwith a pair of outwardly open U-sectioned vertical channels and a pairof abutments spaced apart in the direction of movement of the carriagealong the rail. Each of the plates 3g, 3g" constituting the respectivepallet 3g can then include a respective inwardly turned projection 3kreceived in the channels 31 and displaceable therealong to permit thevertical movement of the rack 3 and the pallets thereof, as describedabove. The ribs 3h thus constitute transversely spaced longitudinallyextending guide elements parallel to the rail; the stages of the rack(not shown in FIGS. 1 and 2) can then be provided with correspondingtransversely spaced longitudinally extending guide elements. The rack 3is subdivided into two laterally spaced portions 3' and 3" so as toleave a. central clearance in the plane of the rail 70b to permit thearm 70a to shift between the rack portions 3' and 3" in the direction ofthe press 1. The alignment plates 3i are constituted as heads whose arms3 connect them with the arm 70c (FIGS. 1 and 2). The channels 3l fromanother arm 70d which is supported from a carriage 70:2 and by means ofwhich the pallets 3g are advanced into the press 1. The carriage 70e hasa drive roller 70 rotated via a belt 70g by a motor 70b. The arms 70cand 70d are thus mutually entrainable with lost-motion or play so as topermit the heads 31' to align the right-hand edges of the stacks uponthe pallets 3g during an initial movement of the arm 70c and the heads3i to the left. Further movement of this arm in the direction of arrow70: is effected via arm 70d which carries the pallets into the presswhile developing a spacing between the heads 3i and the aforementionedrear edge of the respective stacks sufficient to accommodate thestripper arms 7a and 7b. The heads 3i can each be provided with recessesreceiving the corresponding longitudinal elements or ribs 311 and ininterleaved relationship therewith so as to ensure positive entrainmentof the stacks while elastic surfaces can be disposed upon their abutmentfaces, as described in the last-mentioned copending application.

H old-down mechanism According to the present invention, each of thepresscharging tablets is provided with a hold-down mechanism best seenin FIGS. 3-6 but designated generally at 10 in FIG. 2 on each side ofthe press-charging station. The hold-down mechanism comprises raisableand lowerable hold-down plates 11 extending generally parallel to eachof the charging tablets and assigned to each of the presscharging stagesat both sides 3', 3" of the station 2. A lever linkage 12 (FIG. 4)connects the plates with the raising and lowering device as generallydesignated at 13 for the simultaneous lifting of all of the hold-downplates. A hydraulic mechanism 14 is provided for lifting the hold-downplates independently of one another when the respective tablets aredisposed in the region of the charging level 9 for insertion of therespective stacks of relatively thin laminatable material into thecharging station and upon these tablets.

The hold-down plates 11 are composed of sheet metal with reinforcingprofiles welded thereto or formed integrally thereon at the oppositeedges 15 (FIGS. 3 and 4) of each rectangular plate. The lever linkage 12of each of the plates 11 of the respective stages is provided with apair of shafts 16 (FIGS. 3 and 4) extending transversely to thedirection of movement of the tablets and the stacks of laminatablesheets carried by each of them during the press-charging action. Theshafts 16 each have levers or arms 17 (FIG. 4) which are connected bybushings 20 slid axially into the shafts 16 and locked for rotationtherewith by means of keys 21. A pair of such arms 17 are provided inaxially spaced relationship along each of the shafts 16 so that eachpress-charging stage comprises a pair of such shafts 16 in laterallyspaced relationship in the direction of movement of the stacks (arrow aof FIG. 4) on each of the halves 3, 3" of the charging device. The arms17 then extend radially from their respective shafts 16 toward theopposite ends of the tablets.

The hold-down device of only a single charging stage at one side 3 ofthe charging station 2 can be seen in FIGS. 3 and 4. The shafts 16 arealso keyed to respective actuating levers 18 via sleeves or bushings 18aand keys 18b for coupling the hold-down plates 11 with theplateelevating system 13. The shafts 16 are journalled in conventionalpillow blocks 19 directly upon the respective halves 3 and 3" of thecharging rack 3, the latter being constituted of truss or frameconstruction, as will be apparent from FIG. 1.

The extremities of the swinging arms- 17 remote from the respectiveshafts 16 are provided with longitudinal slots 22 receiving pins 23adapted to pivotally connect the arms 17 to the hold-down plates 11. Forthis purpose, the holddown plates 11 have trunnions 24 in the form ofpairs of lugs receiving the respective pins 23 and lying on oppositesides of the respective lever 17. The lug 24 can also be longitudinallyslotted.

The swinging arms or levers 18 are joined via slot andpin connections 25(FIG. 3) With a sliding block 26 vertically shiftable along an actuatingmember 28 (FIGS. 1, 3 and 4) extending along each of the rack halves 3',3" and adapted to actuate the hold-down plates. The tubular actuatingmember 28 is provided with radial pins 29 assigned to each of the slides26 of the respective stages and engaging them with lost-motion. Thus,the extremities of pins 29 lying beyond the periphery of the actuatingmember 28 can be received in axially extending slots 30 of the slides 26so that the upper and lower edges 27a and 27b of these slots formabutments engageable by the pin 29. The abutments 27a and 27b and thepins 29 define the stroke of the slides 26 upon the actuating member 28.

In the position of the device illustrated in FIG. 3, the hold-down plate11 (as representative of all of the holddown plates) has been liftedagainst the next higher stage 4 of the charging station to provide amaximum clearance C between itself and the respective tablet whosereceiving surface is represented by the dot-dash line T in FIG. 3. Forthis purpose, the actuating member 28 is drawn downwardly (arrow 28a)with respect to the rack 3 so that all the pins 29 engage the lowerabutments 27a of the respective slides 26 and likewise draw them downwardly to raise all of the plates 11. The levers 18 on the left-handside (FIG. 3) of the actuating member 28 are thus swung in the clockwisesense while levers 18 on the right-hand side of member 28 are swung inthe counterclockwise sense to elevate the plates 11 and bring them tobear against the underside of the next-charging stage 4.

For simultaneous actuation of the plates 11, we provide a fluid-operateddevice, e.g. a pneumatic or hydraulic cylinder 31 whose piston rod 32 ishinged at 33 to a lever 34; the latter is fulcrumed at 38 to abifurcated lug 37 mounted on. the channel irons 38a of the respectiverack half 3'. The other extremity of lever 34 is pivotally connected viapin 35 to a bifuracted lug 35a threaded into a bushing 35!) at the lowerextremity of the actuating member 28. The latter can be guided at spacedlocations in slide bearing 36, only one of which can be seen in FIG. 5.The double-acting cylinder 31 is energizable via a hydraulic line 31a toshift the actuating member 23 relative to the rack frame 3' and thusraise or lower the plates 11. The hydraulic or pneumatic mechanism 31,32 etc. can be disposed below all of the charging stages 4 and can beprovided with a bifurcated head 33 for pivotal con-. nection via a pin33a with the lever 34.

The system can be arranged as illustrated generally in FIG. 2 such thattwo tensionable actuating members 28 are provided, one for each half 3,3" of the rack so that the charging plate of each stage is subdividedcorrespondingly into two halves whereby a space is left between them ifor advance of the press-charging tablets and the arms 70c and 70d.Thus, the fluid-responsive cylinders 31 of both the actuating members 28can be connected in parallel for joint operation or can be actuated viarespective hydraulic lines for independent operation. It will beunderstood, moreover, that the hydraulic device 31, 32 can be coupleddirectly with the bifurcated lug 3511 without the aid of the lever 34,if desired. It is also possible to replace the hydraulic means 31 and 32by a mechanical system having, for example, an actuating lever connectedwith the fulcrum pin 38 which can be keyed to the lever 34.

The mechanism 14 for individually raising the plates 11 is illustratedin FIG. 6 and comprises a double-acting hydraulic or pneumatic cylinder39 whose piston rod 44 has a bifurcated head 45 receiving a lever arm 46and is articulated thereto at 45a. The lever 46 is swingably mounted inthe region of the charging level 9 upon a shaft 46a and has an extremity46b adapted to depress the block 26 and thus raise the plate as eachstage 4 is aligned with the stack-feed device. For this purpose, theslides 26 are each provided with a respective pin 26a engageable by theend 4617 of lever 46 during clockwise movement thereof upon energizationof the hydraulic cylinder 39. The hydraulic cylinders 31 and 39 areprovided with respective lugs 43, 43' for swingably mounting them uponthe trunnions 42, 42 of the respective rack half 3 via pins 41, 41'.

Operation In accordance with the principles of the present invention,the plant illustrated in FIGS. 1-6 can be considered to operateessentially as follows:

Assuming that the charging rack 3 is in its lowermost position, therespective charging pallets are successively fed with stacks oflaminatable sheet material from a feeding device of the type describedin the copending application Ser. No. 534,231, filed March 14, 1966 andentitled Apparatus for the Charging of Multiplaten Presses. As eachstage 4 is aligned with the feed device, the hydraulic cylinder 39adjacent the rack is energized so that the lever 46 engages the pin 26aof the respective slide 26 and lowers the latter within the most-motionstroke or play of the slide to elevate the respective plates 11 andprovide the maximum clearance C, thereby'permitting the stacks oflaminatable sheets to be inserted into the respective pallets. Cylinder39 then rotates the lever 46 in a counterclockwise sense to release thestop 26a and permit elevation of the slide (dot-dash position in FIG. 6)whereby the plate 11 is clamped under its weight against the stack ofmaterial upon the respective charging stage. The rack 3 then is liftedand the process is repeated for each of the stacks until the rack 3 isfilled. The stacks are then advanced into the press after straighteningof their rearmost edges via the means and technique set forth in ourcopending application Ser. No. 534,324, filed March 15, 1966, andentitled, Press-Charging Apparatus. Prior to the advance of the pallets,however, the cylinders 31 are energized to draw members 28 downwardlyand raise the plates 11 of all stages simultaneously, thereby releasingthe stacks for advance into the press.

Th invention described and illustrated is believed to admit of manymodifications within the ability of persons skilled in the art, all suchmodifications being considered within the spirit and scope of theappended claims.

We claim:

1. In a system for the charging of a multiplaten press, the improvementwhich comprises:

a vertically displaceable press-charging station disposed adjacent saidmultiplaten press and provided with a multiplicity of charging stagescorresponding in num her to the platens of said press for deliveringlayers of material to be compressed from said stages to said platens inan elevated position of said press-charging station, said press-chargingstation being raisable for successive positioning of said stages at afeeding level for successively depositing corresponding layers ofmaterial upon said stages;

hold-down means carried by said press-charging station and including arespective vertically movable ho'd down element overlying each of saidstages and actuatable for compressing the respective layers against therespective stages;

first actuating means for collectively lifting said holddown elementsupon elevation of said station to shift the respective layers into saidpress; and

second actuating means operable to raise the holddown elements of eachstage independently of the other hold-down elements for receiving therespec tive layers between the respective element and stage at saidfeeding level.

2. The improvement defined in claim 1, further comprising a leverlinkage connecting each of said holddown elements with said fi stactuating means, said second actuating means being selectivelyengageable with each of said arrangements upon positioning of therespective stage at said feed level.

3. The improvement defined in claim 2 Wh6Ti1 said press-charging stationincludes a rack carrying said stages and said lever arrangements eachcomprising a respective pair of spaced-apart shafts extendingperpendicularly to the direction of displacement of the layers into saidpress and journaled on said rack, a pair of swingable arms keyed to eachof said shafts and pivotaily connected to the respective hold-downelement, and a pair of actuating levers keyed to said shafts anddisplaceable by said actuating means for raising and lowering saidhold-down elements.

4. The improvement defined in claim 3 wherein each of longitudinallyextending slot and the other of said meazne s carrying a pin slidablealong said slot.

5. The improvement defined in c aim 3 wherein said first actuating meansincludes a verticaly shiftable elongated actuating member and said leverarrangements each include a respective slide body vertically shiftableon said member and eatrainable therewith, said levers of each of saidlever arrangements being pivotaily connected to the respective slidebodies, said actuating member and said bodies being mutually en ageablewith lost-motion in vertical irection.

6. The improvement defined in claim 5 wherein said first actuating meansincludes fluid-responsive means coupled with said actuating member fordisplacing same in vertical direction.

7. The improvement defined in claim 5 wherein said second actuatingmeans includes fluid-responsive means engageable with each of said slidebodies upon the positioning of the respective stage at said feed levelfor rotating said shafts independently of movement of said actuatingmember.

8. The improvement defined in claim 2 wherein each of said hold-downelements is constituted by a plate overlying the respective stage.

9. The improvement defined in claim 8, further comprising reinforcingmeans formed along the periphery of said plate for stiffening same.

it The improvement defined in claim 1 wherein:

said press-charging station includes a vertically displaceable racksubdivided laterally of the direction of displacement of said layersinto said press into two rack portions, each of said stages including abipartite tablet slidable into said press and withdrawable therefrom todeposit the respective layers upon the respective platens, at least onearm depending between said portions for advancing said tabletssimultaneously into said press, said tablets being en gageable by saidarm but vertically movable relatively thereto, and means for raising andlowering said rack; said system further comprising strip means betweensaid press-charging station and said multiplaten press and including aplurality of strip members respectively assigned to said said stages andoperable upon insertion of said tablets into said press to retain saidlayers therein upon withdrawal of said tablets; Said elements are eachconstituted by a pair of plates overlying the tablets of the respectivestages and received in the respective rack portion and adapted to clampthe respective layers against the respective tablets in a loweredcondition of each of said plates; said hold-down means furthercomprising a respective pair of shafts assigned to each of said platesand journaled in the respective rack portion while extendingtransversely of the direction of displacement of said tablets to advancesaid layers into said press and being spaced apart in said direction, apair of spaced-apart arms keyed to each of said shafts and hingedlyconnected to the respective plate for swinging movement about axesparallel to those of said shafts for generally parallel movement of saidplates, actuating lever keyed to each of said shafts, and a respectiveslide body pivotally connected to the actuating levers of the shafts ofeach plate; said first actuating means includes a respective elongatedactuating member vertically shiftable upon the respective rack pontionsand slidably receiving said bodies, means forming a lost-motionconnection between each of said bodies and a respective actuatingmember, a respective fluid-responsive piston-andcylinder arrangementdisposed at one end of each of said actuating members, and link meansincluding a lever fulcrumed on the respective rack portion andconnecting each of said piston-and-cylinder arrangements with therespective actuating members; and

said second actuating means includes a fixedly positionedpiston-and-cylinder arrangement successively engageable with said bodiesfor raising said plates independently of one another.

References Cited UNITED STATES PATENTS 2,704,608 3/1955 Graf et a1.2l4l6.6 3,019,478 2/1962 Erickson et al. 21416.4 XR 3,024,721 3/1962Brooks -l37 XR GERALD M. FORLENZA, Primary Examiner.

R. B. JOHNSON, Assistant Examiner.

1. IN A SYSTEM FOR THE CHARGING OF A MULTIPLATEN PRESS, THE IMPROVEMENTWHICH COMPRISES: A VERTICALLY DISPLACEABLE PRESS-CHARGING STATIONDISPOSED ADJACENT SAID MULTIPLATEN PRESS AND PROVIDED WITH AMULTIPLICITY OF CHARGING STAGES CORRESPONDING IN NUMBER TO THE PLATENSOF SAID PRESS FOR DELIVERING LAYERS OF MATERIAL TO BE COMPRESSED FROMSAID STAGES TO SAID PLATENS IN AN ELEVATED POSITION OF SAIDPRESS-CHARGING STATION, SAID PRESS-CHARGING STATION BEING RAISABLE FORSUCCESSIVE POSITIONING OF SAID STAGES AT A FEEDING LEVEL FORSUCCESSIVELY DEPOSITING CORRESPONDING LAYERS OF MATERIAL UPON SAIDSTAGES; HOLD-DOWN MEANS CARRIED BY SAID PRESS-CHARGING STATION ANDINCLUDING A RESPECTIVE VERTICALLY MOVABLE HOLDDOWN ELEMENT OVERLYINGEACH OF SAID STAGES AND ACTUATABLE FOR COMPRESSING THE RESPECTIVE LAYERSAGAINST THE RESPECTIVE STAGES; FIRST ACTUATING MEANS FOR COLLECTIVELYLIFTING SAID HOLDDOWN ELEMENTS UPON ELEVATION OF SAID STATION TO SHIFTTHE RESPECTIVE LAYERS INTO SAID PRESS; AND SECOND ACTUATING MEANSOPERABLE TO RAISE THE HOLDDOWN ELEMENTS OF EACH STAGE INDEPENDENTLY OFTHE OTHER HOLD-DOWN ELEMENTS FOR RECEIVING THE RESPECTIVE LAYERS BETWEENTHE RESPECTIVE ELEMENT AND STAGE AT SAID FEEDING LEVEL.